Rhabdomyolysis induced by epsilon-aminocaproic acid

To report a case of rhabdomyolysis associated with epsilon-aminocaproic acid (epsilon-ACA).

A 33-year-old female patient with chronic granulocytic leukemia was treated with epsilon-ACA for approximately 3.5 months for thrombocytopenic bleeding. The initial dosage was 4 g po q6h. One month after an increase in dosage to 5 g po 14h the patient developed severe lower extremity myalgia and marked weakness. Laboratory investigations revealed an elevated creatine kinase (CK), lactate dehydrogenase (LDH). aspartate aminotransferase (AST), and myoglobinemia. Epsilon-ACA was thought to be the causative agent and was discontinued. The patient received intravenous fluids to minimize renal damage due to myoglobin. Serum enzyme concentrations did not return to normal. The patient died of a central nervous system hemorrhage 1 week after the epsilon-ACA was discontinued.

There were 31 cases of epsilon-ACA-induced myopathies published in the literature (MEDLINE) from 1972 to June 1995. Of these, 10 cases were reviewed. In all cases, patients received epsilon-ACA in doses ranging from 16 to 36 g/d for more than 28 days. Clinical findings varied from extreme muscle weakness to myopathic changes in electromyelograms. All patients recovered following discontinuation of epsilon-ACA.

Long-term therapy with high-dose epsilon-ACA may produce muscle weakness or rhabdomyolysis. Patients who require long-term, high-dose epsilon-ACA therapy should be monitored for myoglobinuria and changes in serum CK, LDH, and AST, for myoglobinemia, for decreases in muscle strength, and/or for myalgia. Significant changes in these parameters compared with baseline values should suggest a need to discontinue epsilon-ACA therapy.